Most switching power converters are employed to convert an input voltage into an appropriate output voltage through controlling a switch module to switch on and off, thereby regulating power transmitted to a load.
However, when the load changes rapidly, the output voltage may widely vary. For instance the output voltage may drop largely if the load gets heavier and requires a larger current. In this circumstance, it is desired that the output voltage can be regulated to restore to its desired value as quickly as possible.